Publications by Toni Mikael Lassila

Improved hybrid/GPU algorithm for solving cardiac electrophysiology problems on Purkinje networks

Alfio Quarteroni, Christian Vergara, Toni Mikael Lassila

Cardiac Purkinje fibers provide an important pathway to the coordinated contraction of the heart. We present a numerical algorithm for the solution of electrophysiology problems across the Purkinje network that is efficient enough to be used in in silico s ...

Wiley2017

Integrated Heart-Coupling multiscale and multiphysics models for the simulation of the cardiac function

Alfio Quarteroni, Ricardo Esteban Ruiz Baier, Toni Mikael Lassila, Simone Rossi

Mathematical modeling of the human heart and its function can expand our understanding of various cardiac diseases, which remain the most common cause of death in the developed world. Like other physiological systems, the heart can be understood as a compl ...

Elsevier Science Sa2017

Isogeometric approximation of cardiac electrophysiology models on surfaces: An accuracy study with application to the human left atrium

Alfio Quarteroni, Luca Dede', Toni Mikael Lassila, Alessandro Samuele Patelli, Andrea Bartezzaghi

We consider Isogeometric Analysis in the framework of the Galerkin method for the spatial approximation of cardiac electrophysiology models defined on NURBS surfaces; specifically, we perform a numerical comparison between basis functions of degree p >= 1 ...

Elsevier2017

A coupled 3D-1D numerical monodomain solver for cardiac electrical activation in the myocardium with detailed Purkinje network

Alfio Quarteroni, Christian Vergara, Toni Mikael Lassila

We present a model for the electrophysiology in the heart to handle the electrical propagation through the Purkinje system and in the myocardium, with two-way coupling at the Purkinje-muscle junctions. In both the subproblems the monodomain model is consid ...

Elsevier2016

Accurate solution of Bayesian inverse uncertainty quantification problems combining reduced basis methods and reduction error models

Andrea Manzoni, Toni Mikael Lassila, Stefano Pagani

2016

Efficient Numerical Schemes for Computing Cardiac Electrical Activation over Realistic Purkinje Networks: Method and Verification

Alfio Quarteroni, Christian Vergara, Toni Mikael Lassila

We present a numerical solver for the fast conduction system in the heart using both a CPU and a hybrid CPU/GPU implementation. To verify both implementations, we construct analytical solutions and show that the L-2-error is similar in both implementations ...

Springer-Verlag2015

Thermodynamically consistent orthotropic activation model capturing ventricular systolic wall thickening in cardiac electromechanics

Alfio Quarteroni, Ricardo Esteban Ruiz Baier, Toni Mikael Lassila, Simone Rossi, Adélia Sequeira

The complex phenomena underlying mechanical contraction of cardiac cells and their influence in the dynamics of ventricular contraction are extremely important in understanding the overall function of the heart. In this paper we generalize previous contrib ...

Elsevier2014

A reduced computational and geometrical framework for inverse problems in haemodynamics

Alfio Quarteroni, Gianluigi Rozza, Andrea Manzoni, Toni Mikael Lassila

The solution of inverse problems in cardiovascular mathematics is computationally expensive. In this paper we apply a domain parametrization technique to reduce both the geometrical and computational complexity of the forward problem, and replace the finit ...

Wiley-Blackwell2013

Boundary control and shape optimization for the robust design of bypass anastomoses under uncertainty

Alfio Quarteroni, Gianluigi Rozza, Andrea Manzoni, Toni Mikael Lassila

We review the optimal design of an arterial bypass graft following either a (i) boundary optimal control approach, or a (ii) shape optimization formulation. The main focus is quantifying and treating the uncertainty in the residual flow when the hosting ar ...

EDP Sciences2013

Model order reduction in fluid dynamics: challenges and perspectives

Alfio Quarteroni, Gianluigi Rozza, Andrea Manzoni, Toni Mikael Lassila

This chapter reviews techniques of model reduction of fluid dynamics systems. Fluid systems are known to be difficult to reduce efficiently due to several reasons. First of all, they exhibit strong nonlinearities – which are mainly related either to nonlin ...

Springer2013